Interface Engineering in Organic Field-Effect Transistors

Interface Engineering in Organic Field-Effect Transistors

Systematic summary of advances in developing effective methodologies of interface engineering in organic field-effect transistors, from models to experimental techniques

Interface Engineering in Organic Field-Effect Transistors covers the state of the art in organic field-effect transistors and reviews charge transport at the interfaces, device design concepts, and device fabrication processes, and gives an outlook on the development of future optoelectronic devices.

This book starts with an overview of the commonly adopted methods to obtain various semiconductor/semiconductor interfaces and charge transport mechanisms at these heterogeneous interfaces. Then, it covers the modification at the semiconductor/electrode interfaces, through which to tune the work function of electrodes as well as reveal charge injection mechanisms at the interfaces.

Charge transport physics at the semiconductor/dielectric interface is discussed in detail. The book describes the remarkable effect of SAM modification on the semiconductor film morphology and thus the electrical performance. In particular, valuable analyses of charge trapping/detrapping engineering at the interface to realize new functions are summarized.

Finally, the sensing mechanisms that occur at the semiconductor/environment interfaces of OFETs and the unique detection methods capable of interfacing organic electronics with biology are discussed.

Specific sample topics covered in Interface Engineering in Organic Field-Effect Transistors include:

• Noncovalent modification methods, charge insertion layer at the electrode surface, dielectric surface passivation methods, and covalent modification methods
• Charge transport mechanism in bulk semiconductors, influence of additives on materials’ nucleation and morphology, solvent additives, and nucleation agents
• Nanoconfinement effect, enhancing the performance through semiconductor heterojunctions, planar bilayer heterostructure, ambipolar charge-transfer complex, and supramolecular arrangement of heterojunctions
• Dielectric effect in OFETs, dielectric modification to tune semiconductor morphology, surface energy control, microstructure design, solution shearing, eliminating interfacial traps, and SAM/SiO₂ dielectrics

A timely resource providing the latest developments in the field and emphasizing new insights for building reliable organic electronic devices, Interface Engineering in Organic Field-Effect Transistors is essential for researchers, scientists, and other interface-related professionals in the fields of organic electronics, nanoelectronics, surface science, solar cells, and sensors.

Xuefeng Guo received his Ph.D. in 2004 from the Institute of Chemistry, Chinese Academy of Sciences, Beijing. From 2004 to 2007, he was a postdoctoral research scientist at the Columbia University Nanocenter. He joined the faculty as a professor under ?Peking 100-Talent? Program at Peking University in 2008. In 2012, he won the National Science Funds for Distinguished Young Scholars of China. His current research is focused on functional nanometer/molecular devices. Professor Xuefeng Guo has authored over 195 scientific publications and has received numerous scientific awards, including the First Award of First prize of Ministry of Education Natural Science Award and the XPLORER PRIZE.

Hongliang Chen received his Ph.D. in 2016 from the College of Chemistry and Molecular Engineering, Peking University, under the guidance of Professor Xuefeng Guo. From 2016 to 2018, he worked as a research scientist at Core R&D department in Dow Chemical Company. Then he moved to Northwestern University in United States and worked as a postdoctoral research fellow in Professor Sir Fraser Stoddart?s group from 2018 to 2021. He joined Zhejiang University as an assistant professor since June 2021. His research interest is focused on organic functional devices and molecular electronics.

1. INTRODUCTION
1.1. Different interfaces in OFETs
1.2. Brief historic overview of interface engineering in OFETs
1.3. Scope of the book

2. INTERFACIAL MODIFICATION METHODS
2.1. Noncovalent modification methods
2.1.1. Charge insertion layer at the electrode surface
2.1.2. Dielectric surface passivation methods
2.2. Covalent modification methods
2.2.1. SAM modification of electrodes
2.2.2. SAM modification of dielectrics
2.3. Efforts in developing new methods

3. SEMICONDUCTOR/SEMICONDUCTOR INTERFACE
3.1. Charge transport mechanism in bulk semiconductors
3.2. Influence of additives on materials nucleation and morphology
3.2.1. Solvent additive
3.2.2. Nucleation agent
3.2.3. Crystallization template
3.2.4. Insulating polymer (Phase separation)
3.2.5. Nanoconfinement effect
3.3. Enhancing the performance through semiconductor heterojunctions
3.3.1. Planar bilayer heterostructure
3.3.2. Ambipolar charge-transfer complex
3.3.3. Supramolecular arrangement of heterojunctions
3.4. Integrating molecular functionalities into electrical circuits
3.4.1. Interface charge-transfer doping
3.4.2. Charge trapping-induced memory effects
3.4.3. Photochromism-induced switching effect

4. SEMICONDUCTOR/ELECTRODE INTERFACE
4.1. Energy level alignment at the organic/metal interface
4.2. Work function tuning for better contact
4.2.1. SAM modification
4.2.2. CIL modification
4.2.3. Polymer-based electrodes
4.2.4. Carbon nanomaterial-based electrodes
4.2.5. Covalent bond formation at the molecular level
4.3. Installing molecular functionalities
4.3.1. Switching effect
4.3.2. Surface energy control

5. SEMICONDUCTOR/DIELECTRIC INTERFACE
5.1. Dielectric effect in OFETs
5.2. Dielectric modification to tune semiconductor morphology
5.2.1. Surface energy control
5.2.2. Microstructure design
5.2.3. Solution shearing
5.3. Eliminating interfacial traps
5.3.1. SAM/SiO2 dielectrics
5.3.2. SAM/high-k dielectrics
5.3.3. Nanodielectrics
5.4. Integrating new functionalities
5.4.1. Photoresponsive dielectric
5.4.2. Pressure-responsive dielectric
5.4.3. Thermally-responsive dielectric
5.4.4. Magnetically-responsive dielectric
5.4.5. New memory effect

6. SEMICONDUCTOR/ENVIRONMENT INTERFACE
6.1. Trap mechanism of OFETs-based sensors
6.2. Device structure optimization
6.2.1. Monolayer functionalization
6.2.2. Bilayer heterojunction approach
6.2.3. Remote floating gate
6.2.4. Encapsulant treatment
6.3. Chemical functionalization for specific detection
6.3.1. Gas sensor
6.3.2. Liquid sensor

7. INTERFACING ORGANIC ELECTRONICS WITH BIOLOGY
7.1. Semiconducting biomaterials
7.2. OFETs-based biosensors
7.2.1. OFET-based biomolecular sensors
7.2.2. OFET-based cell sensors
7.3. The rise of plastic bioelectronics

8. SUMMARY AND OUTLOOK
8.1. Main challenges and open questions
8.1.1. New challenges in molecular design
8.1.2. High-quality OSC films: self-assembly control
8.1.3. High-performance scalable flexible optoelectronics
8.1.4. Exploration of novel structures: organic/2D heterostructures and vertical structures
8.1.5. Stability in aqueous media and thermal stability in hygienic applications
8.1.6. Accurate mobility extraction in OFETs
8.1.7. Multifunctional sensor systems
8.2. Outlook